             [the-little-clojurian.chapter2 :refer :all]
             [the-little-clojurian.chapter3 :refer :all]
             [the-little-clojurian.chapter4 :refer :all]))
+
+(declare equal?)
 
 (with-test
   (def rember* 

  (is (= (equal? '(a) '(a)) true))
  (is (= (equal? '(a) '(b)) false)))

;; exercises
(with-test 
  (def replace* 

    (fn [l1 l2] 
      (cond (and (null? l1) (null? l2)) true
            (or (null? l1) (null? l2)) false
            :else (and (equal? (car l1) (car l2))
                       (eqlist? (cdr l1) (cdr l2))))))
  
  (is (= (eqlist? '() '()) true))
